Hello L4 Hackers

I am working on a project with L4Re in Pandaboard for my College Final Project. And right now i am in a stuck.

So far, i have already know how to boot, print and read from the serial port (UART3) of pandaboard. But i can't understand the fundamental / basic of L4Re itself.

Like how to make a new program outside the main program of "hello" (i am using hello code all of this time to experimenting). And also how to access the memory of the host computer using L4Re code.
Because the main goal of the project i am working on is be able to access the GPIO of Pandaboard.

And also, is there is any way to recompile L4Re without recompiling all of the module it use. Because in my computer it took a time to recompile even the change is only a line of code

Can anyone teach or show me how to make it ? Actually i already have read the documentation of L4Re, but i am still having a hard time understanding it.

Thank you for any answer and feedback.